The Internet and Intranet have come to establish the positions as the main media for dispatching information and exchanging opinions, and the amount, versatility, and promptness thereof have become the “must” for conducting investigations/analysis of various kinds of information. In the works such as collecting necessary information on the net and classifying each piece of information from a significant viewpoint, it is effective to make and use ontology. Ontology is a definition of properties of a given concept, or a definition of relationships between concepts or phenomena. Further, there is also a case where the ontology includes instances which satisfy the defined relationships.
Through expressing the ontology by using a certain formal descriptive method such as OWL (Web Ontology Language) recommended by World Wide Web Consortium (W3C), comparison and integration of a plurality of kinds of ontology can be done easily. In general, the ontology is made manually. However, there is a limit for manually investigating all the properties (functions and kinds of characteristics) of each of a great number of products, for example, and for manually updating kinds of properties and definitions of the products such as portable telephones every time whose properties are changed frequently.
In order to reduce the labor for building the ontology, first, a technique for making it easier to collect subject matters to be the elements of the ontology, properties thereof, and objects is important. As a technique for automatically collecting words and phrases showing the properties (property expressions) of a specific kind of targets, there is a technique disclosed in Patent Document 1. In Patent Document 1, having a set of a specific kind of documents prepared in advance as input, words and phrases frequently appear in the document set are extracted as property expressions. Further, in Patent Document 1, words and phrases of high co-occurrence characteristic existing in the vicinity of each of the extracted properties are extracted as objects which correspond to the respective properties.
Patent Document 2 discloses a method for extracting properties and objects using the ontology. This method prepares ontology showing a specific concept in advance, and extracts properties and objects which go along with conditions expressed by the ontology. With the above-described techniques, the properties of various targets and values of each of the properties can be automatically collected from the Internet and databases.
Further, Patent Document 3 discloses a method which gives important degrees to each property of the ontology, and extracts information regarding only the property whose important degree exceeds a prescribed threshold value. However, the judging reference for determining information regarding which property is to be extracted is only a single threshold value for the important degree, and there is no device disclosed for determining the object to be extracted based on the mutual dependent relationship between the objects.
Non-Patent Document 1 discloses a method which automatically determines the corresponding properties in different frames for a set of a plurality of kinds of targets, properties, and objects written as frames. However, there is no method provided to integrate each of the frames as ontology.
Regarding terms of a specific field, Non-Patent Document 2 discloses a method for automatically creating a thesaurus in which synonyms, narrow-sense words, broad-sense words, and related words are defined. However, this method is limited only to creating the thesaurus, and it is not capable of collecting the ontology for describing the concept and instances thereof and organizing those.
Non-Patent Document 3 provides a device for automatically converting a table written in CSV (Comma Separated Value) into ontology conforming to OWL described above, and it is a feature of that device to be able to easily generate correct ontology as syntaxes of OWL without having detailed knowledge of OWL. However, the device is not provided with a function capable of supplementing incomplete properties and vocabularies of the ontology and a function capable of detecting relationships between the properties and between objects and integrate those or supporting the integration thereof.
The conventional ontology creating methods such as those described in Non-Patent Document 2 and Non-Patent Document 3 are achieved as an ontology creating unit 20 which includes a data input device 1 for inputting data as the base for ontology, an ontology-making device 2 for converting the input data into a form of ontology, and an ontology storage device 3 for storing the ontology generated by the conversion, as shown in FIG. 31. However, with the use of only the constitution of such ontology creating unit 20, it is necessary to write in advance the characteristics and restrictions of each property that are supposed to be in the ontology and all the information regarding the structure of the ontology into the input data. Preparation of such data is a heavy burden on the users.
Alternatively, the ontology creating unit 20 can be made into a constitution as in FIG. 32 through further providing an ontology editing system that is disclosed in Non-Patent Document 4. This makes it possible to correct and integrate the already-generated ontology manually. However, when the number of generated ontology becomes large, it becomes difficult to perform editing works on a terminal screen manually.    Patent Document 1: Japanese Unexamined Patent Publication 2000-137720    Patent Document 2: Japanese Unexamined Patent Publication 2000-207407    Patent Document 1: Japanese Unexamined Patent Publication 2005-148886    Non-Patent Document 1: ITOH, UEDA, IKEDA, “Example Based Frame Mapping Applied Information Agents for Distributed Sources” IEICE Journal, Vol. J81-D-I, No. 5, pp. 433-442, 1998    Non-Patent Document 2: UCHIDA, ISHINO, “Fundamental Study on Automatic Building of Ontology”, The Japanese Society for Artificial Intelligence Material, SIG-SW&ONT-A301-05, 2003    Non-Patent Document 3: Cyber Edge, Media Coverage on Nov. 21, 2006, regarding Sale of “Ontology Generator”, http://www.semanticweb.jp/pub/OntologyGenerator.html    Non-Patent Document 4: “Hozo—Operation Manual for Ontology Editor”, http://www.ei.sanken.osaka-u.ac.jp/hozo/manual/manual.html